On the Evolution of GGHN Cipher
In this paper we study the GGHN stream cipher presented in CISC 2005. This cipher has been motivated from RC4 with the idea to obtain further speed-up by considering word-oriented keystream output instead of byte-oriented ones. We prove that there exist a large number of short cycles of length equal to the length of the state array used in the cipher. Then towards having a theoretical analysis of GGHN type evolution, we study a randomized model of this cipher. Using Markovian process, we show how this model evolves to all zero state much faster than what is expected in an ideal scenario.
KeywordsCryptanalysis GGHN RC4 Short Cycles Stream Cipher
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- 1.Finney, H.: An RC4 cycle that can’t happen. Posting to sci.crypt. (September 1994)Google Scholar
- 3.Grinstead, C.M., Snell, J.L.: Introduction to Probability (2006), http://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/book.html